1. Field of the Invention
The present invention relates to an electromagnetic relay, and in particular, to an assembly structure of an electromagnetic portion to a base and a contact mechanism portion.
2. Description of the Prior Art
Conventionally, as an electromagnetic relay, there is one, wherein an electromagnet portion 103 is accommodated, secured into the central portion of a convex 101a of a box-shaped base 101, and contact blocks 102, 102 are accommodated, secured onto both the side portions thereof to have contact mechanism portions 106, 106 provided above the electromagnet portion 103 as shown in, for example, FIG. 39 and FIG. 40.
It is to be noted that 104 is a movable iron piece which drives the movable contact pieces 102a, 102a through the pivoting operation in accordance with the energization, deenergization of the electromagnet portion 103 so as to open and close the contact, 105 is a hinge spring for pivotally supporting the movable iron piece 104 in a manner of hinge.
However, in the above-described electromagnetic relay, as spare space was not provided within the base 101 in the accommodating, securing operations of the electromagnet portion 103 and the contact blocks 102, 102 within the concave 101a of the base 101, the electromagnet portion 103 had to be grasped by the contact blocks 102, 102 through the engagement of the positioning projections 103a, 103a projected from both the side ends of the electronic magnet portion 103 into the engagement concave portions (not shown) provided in the opposite inner side faces of the contact blocks 102, 102 so as to depress it into the concave 101a at one time after it has been positioned above the base 101.
Thus, when even one terminal among the terminals of the contact blocks 102 was shifted in position, the electromagnet portion 103 and the contact blocks 102, 102 could not be accommodated within the base 101, thus taking more time in the assembling operation.
Especially, when an automatic assembling operation was effected by machines, there was a problem that the terminal was bent within the concave 101a, defective products were likely to be caused, because the assembling machine was forced to effect the depressing insertion even if the position of the terminal was out of position.
Also, the engagement condition between the positional projections 103a, 103a of the electromagnet portion 103 and the engagement concave portion of the contact blocks 102, 102 or the contact condition between the contact blocks 102, 102 and the base 101 could not be sometimes flush in the respective upper end faces of the contact blocks 102, 102 due to shifts between each other or could be inclined with respect to the yoke of the electromagnet portion 103. Therefore, there was a problem of producing the defective products in that the positional relation between the contact portions 106, 106 and the movable iron piece 104 of the electromagnet portion 103 was shifted in the design center to prevent the operation characteristics from being provided within the standard, the stage difference was caused in the position of the respective stationary contacts of the contact blocks 102, 102 to prevent the contact pressure from staying within the standard value, and so on.
As the respective terminals of the contact blocks 102, 102 were secured by insert molding (closed molding), there were nothing to do about later adjustments and coordinations even if the shift were caused in the size relation after the assembling operation as described hereinabove, with difficulties in improvements in the yield.